Activating transcription factor 3 regulates canonical TGFβ signalling in systemic sclerosis
Activating transcription factor 3 regulates canonical TGFβ signalling in systemic sclerosis
复制标题
DOI：
10.1136/annrheumdis-2014-206214
复制
发表时间：
2016-03-01
影响因子：
27.4
通讯作者：
Distler, Joerg H. W.
中科院分区：
文献类型：
--
作者：
Mallano, Tatjana;Palumbo-Zerr, Katrin;Distler, Joerg H. W.
激活转录因子3 （ATF3）是ATF/ camp响应元件结合（CREB）转录因子家族的一员，可调节细胞对包括氧化应激在内的应激反应。本研究的目的是分析ATF3在系统性硬化症（SSc）成纤维细胞活化中的作用。方法采用反转录定量PCR、western blot和免疫组织化学对ATF3进行分析。用敲除ATF3的成纤维细胞和小鼠来研究ATF3的功能作用。通过敲低实验、报告基因分析和共免疫沉淀来研究ATF3对Smad和激活蛋白1 （AP-1）信号传导的影响。采用染色法、特异性失活法和共免疫沉淀法分析c-Jun的作用。结果TGF β可上调SSc成纤维细胞中ATF3的表达。ATF3缺陷的成纤维细胞对TGF β的敏感性较低，而ATF3异位表达增强了TGF β的促纤维化作用。在机制上，ATF3直接通过TGF β刺激与Smad3相互作用，并以c- jun依赖的方式调节Smad活性。敲除ATF3可保护小鼠免受博莱霉素诱导的纤维化和组成型活性TGF β受体过表达引起的纤维化。对Smad靶基因表达的报告者试验和分析表明，ATF3的结合可调节Smad3的转录活性。我们首次证明了ATF3在纤维化中的关键作用。敲除ATF3基因通过干扰典型的Smad信号传导降低了TGF β对成纤维细胞的刺激作用，并在两种不同的模型中保护小鼠免于实验性纤维化。因此，ATF3可能是SSc分子靶向治疗的候选药物。
Background Activating transcription factor 3 (ATF3), a member of the ATF/cAMP-responsive element binding (CREB) family of transcription factors, regulates cellular response to stress including oxidative stress. The aim of this study was to analyse the role of ATF3 in fibroblast activation in systemic sclerosis (SSc).Methods ATF3 was analysed by reverse transcription quantitative PCR, western blot and immunohistochemistry. ATF3 knockout fibroblasts and mice were used to study the functional role of ATF3. Knockdown experiments, reporter assays and coimmunoprecipitation were performed to study the effects of ATF3 on Smad and activation protein 1 (AP-1) signalling. The role of c-Jun was analysed by costaining, specific inactivation and coimmunoprecipitation.Results Transforming growth factor-beta (TGF beta) upregulates the expression of ATF3 in SSc fibroblasts. ATF3-deficient fibroblasts were less sensitive to TGF beta, whereas ectopic expression of ATF3 enhanced the profibrotic effects of TGF beta. Mechanistically, ATF3 interacts with Smad3 directly on stimulation with TGF beta and regulates Smad activity in a c-Jun-dependent manner. Knockout of ATF3 protected mice from bleomycin-induced fibrosis and fibrosis induced by overexpression of a constitutively active TGF beta receptor I. Reporter assays and analyses of the expression of Smad target genes demonstrated that binding of ATF3 regulates the transcriptional activity of Smad3.Conclusions We demonstrate for the first time a key role for ATF3 in fibrosis. Knockout of the ATF3 gene reduced the stimulatory effect of TGF beta on fibroblasts by interfering with canonical Smad signalling and protected the mice from experimental fibrosis in two different models. ATF3 might thus be a candidate for molecular targeted therapies for SSc.